1. Field
This invention is concerned generally with the field of fermentation and specifically with the use of photometabolism (photosynthesis or biophotolysis) to produce useful products.
2. Prior Art
It is well known that certain microorganisms are capable of producing useful products in the presence of light and certain substrates. Typical of such organisms are the Blue-Green algae (e.g. Anacystis nidulans) which can be used to produce NADPH and certain bacteria which contain hydrogenase and/or nitrogenase enzymes and photosystems. Very generally, the production of products with such microbes involves the conversion (photometabolism) of certain substrates and/or the oxidation of a cofactor such as NADPH or compounds such as reduced ferrodoxins in the presence of a hydrogenase enzyme or a nitrogenase enzyme system. Since several reactants must be available to assure continuous photometabolic production, it can be appreciated that whole cells of photometabolically active microbes may be used to provide one or more contained enzyme systems.
It can also be appreciated, however, that if photometabolism is to be used as a large scale source of products or energy (e.g. H.sub.2), there should be some manner of producing the products or energy on a continuous basis, thus requiring a highly stabilized photometabolically active microbe. It has now been found that such a stabilized microbe system is possible and the system can be used for the continuous production of useful products. Details of the method are described herein.